Fix PR 11709: Change the definition of va_list to meet AAPCS requirement

AAPCS ABI Section 7.1.4 [1] specifies that va_list
should be defined as struct __va_list { void *__ap;};
And in C++, it is defined in namespace std.

[1] http://infocenter.arm.com/help/topic
         /com.arm.doc.ihi0042d/IHI0042D_aapcs.pdf

Patch by Weiming Zhao.

llvm-svn: 165609

2 files changed, 68 insertions, 3 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index a90f0733496..874861872a6 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -5521,6 +5521,65 @@ static TypedefDecl *CreatePNaClABIBuiltinVaListDecl(const ASTContext *Context) {
   return VaListTypedefDecl;
 }
 
+static TypedefDecl *
+CreateAAPCSABIBuiltinVaListDecl(const ASTContext *Context) {
+  RecordDecl *VaListDecl;
+  if (Context->getLangOpts().CPlusPlus) {
+    // namespace std { struct __va_list {
+    NamespaceDecl *NS;
+    NS = NamespaceDecl::Create(const_cast<ASTContext &>(*Context),
+                               Context->getTranslationUnitDecl(),
+                               /*Inline*/false, SourceLocation(),
+                               SourceLocation(), &Context->Idents.get("std"),
+                               /*PrevDecl*/0);
+
+    VaListDecl = CXXRecordDecl::Create(*Context, TTK_Struct,
+                                       Context->getTranslationUnitDecl(),
+                                       SourceLocation(), SourceLocation(),
+                                       &Context->Idents.get("__va_list"));
+
+    VaListDecl->setDeclContext(NS);
+
+  } else {
+    // struct __va_list {
+    VaListDecl = CreateRecordDecl(*Context, TTK_Struct,
+                                  Context->getTranslationUnitDecl(),
+                                  &Context->Idents.get("__va_list"));
+  }
+
+  VaListDecl->startDefinition();
+
+  // void * __ap;
+  FieldDecl *Field = FieldDecl::Create(const_cast<ASTContext &>(*Context),
+                                       VaListDecl,
+                                       SourceLocation(),
+                                       SourceLocation(),
+                                       &Context->Idents.get("__ap"),
+                                       Context->getPointerType(Context->VoidTy),
+                                       /*TInfo=*/0,
+                                       /*BitWidth=*/0,
+                                       /*Mutable=*/false,
+                                       ICIS_NoInit);
+  Field->setAccess(AS_public);
+  VaListDecl->addDecl(Field);
+
+  // };
+  VaListDecl->completeDefinition();
+
+  // typedef struct __va_list __builtin_va_list;
+  TypeSourceInfo *TInfo
+    = Context->getTrivialTypeSourceInfo(Context->getRecordType(VaListDecl));
+
+  TypedefDecl *VaListTypeDecl
+    = TypedefDecl::Create(const_cast<ASTContext &>(*Context),
+                          Context->getTranslationUnitDecl(),
+                          SourceLocation(), SourceLocation(),
+                          &Context->Idents.get("__builtin_va_list"),
+                          TInfo);
+
+  return VaListTypeDecl;
+}
+
 static TypedefDecl *CreateVaListDecl(const ASTContext *Context,
                                      TargetInfo::BuiltinVaListKind Kind) {
   switch (Kind) {
@@ -5534,6 +5593,8 @@ static TypedefDecl *CreateVaListDecl(const ASTContext *Context,
     return CreateX86_64ABIBuiltinVaListDecl(Context);
   case TargetInfo::PNaClABIBuiltinVaList:
     return CreatePNaClABIBuiltinVaListDecl(Context);
+  case TargetInfo::AAPCSABIBuiltinVaList:
+    return CreateAAPCSABIBuiltinVaListDecl(Context);
   }
 
   llvm_unreachable("Unhandled __builtin_va_list type kind");
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 6469c465747..17f1a615f1e 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -2864,6 +2864,7 @@ class ARMTargetInfo : public TargetInfo {
 
   unsigned FPU : 4;
 
+  unsigned IsAAPCS : 1;
   unsigned IsThumb : 1;
 
   // Initialized via features.
@@ -2874,7 +2875,7 @@ class ARMTargetInfo : public TargetInfo {
 
 public:
   ARMTargetInfo(const std::string &TripleStr)
-    : TargetInfo(TripleStr), ABI("aapcs-linux"), CPU("arm1136j-s")
+    : TargetInfo(TripleStr), ABI("aapcs-linux"), CPU("arm1136j-s"), IsAAPCS(true)
   {
     BigEndian = false;
     SizeType = UnsignedInt;
@@ -2937,6 +2938,8 @@ public:
       /// gcc.
       ZeroLengthBitfieldBoundary = 32;
 
+      IsAAPCS = false;
+
       if (IsThumb) {
         // Thumb1 add sp, #imm requires the immediate value be multiple of 4,
         // so set preferred for small types to 32.
@@ -2951,9 +2954,10 @@ public:
 
       // FIXME: Override "preferred align" for double and long long.
     } else if (Name == "aapcs") {
+      IsAAPCS = true;
       // FIXME: Enumerated types are variable width in straight AAPCS.
     } else if (Name == "aapcs-linux") {
-      ;
+      IsAAPCS = true;
     } else
       return false;
 
@@ -3133,7 +3137,7 @@ public:
   }
   virtual bool isCLZForZeroUndef() const { return false; }
   virtual BuiltinVaListKind getBuiltinVaListKind() const {
-    return TargetInfo::VoidPtrBuiltinVaList;
+    return IsAAPCS ? AAPCSABIBuiltinVaList : TargetInfo::VoidPtrBuiltinVaList;
   }
   virtual void getGCCRegNames(const char * const *&Names,
                               unsigned &NumNames) const;